Sorting apparatus for substances of different densities



June 25, 1935. F. J. B. BERRY 2,006,126

SORTING APPARATUS FOR SUBSTANCES OF DIFFERENT DENSITIES Filed Feb. 1, 1933 EJB. BERRY ATTORNEY Patented June 25, 1935 UNITED, STATES SORTING APPARATUS FOR SUBSTANCES OF DIFFERENT DENSITIES Francois Jacques Barthlmy Berry Lille, France Application February 1, 1933, Serial No. 654,749,

- In France February 12, 1932 2 Claims. (Cl. 209-467) The present invention relates to apparatus'for the sorting of substances of different densities, and in particular for the removal of schist, and eventually the intermediate substances, from 5 coal, that is, the removal of the heavy and the partially heavy substances.

It relates particularly to improvements in apparatus of this class which consist of a shaking table with perforated bottom which is upwardly traversed by a continuous current of air, whose action, combined with the shaking, serves to bring the heavy substances to the bottom part of the table from whence they can be evacuated through a suitable orifice, while the light parts,

that is, the screened coal, are discharged by overflowing from the upper part of the table.

According to the improvements in conformity with the invention, the table is connected, directly or by links, with rods driven at one end by a :0 common circular eccentric and separately suspended at the other end by arms pivotally mounted on the main frame. The connecting points of the table with the rods, are chosen in such a manner that the distances from these points to 25 the point of attachment of the rods with the eccentric are proportional to the lengths of the said rods. I g

In this manner, the inner end of'each rod will describe a circumference having the same radius as the eccentric, while the outer end of the rod will describe an arc of a circle whose radius is the length of the suspension arm. Thus the points situated between these ends will describe closed trajectories whose form resembles that of an ellipse, in which the ratio between the large and the small axes will be greater according as such points come nearer the suspended end of the rod, and thus points can be found on said rods, which will describe identical curves and with synchronous motion.

If the shaking table is connected with such intermediate points, it is evident that all points of this table will describe substantially elliptical trajectories, each being the same as those of the several intermediate points on the arms.

The speed of the eccentric and the force of the current of air will depend upon the size of the pieces of substance under treatment, and upon the difierences in the density of the products, whether light, intermediate or heavy.

A form of construction of the sorting apparatus according to the invention is shown by way of example in the accompanying drawing, in which: 55 Fig. 1 is an elevational view of the apparatus.

,Fig. 2 is a diagram illustrating the operation of the apparatus. I

The apparatus for sorting material of differ.- ent densities shown in Fig. l, essentially comprises a table with perforated bottom 10, adapted 5 I to hold, between its raised edges II, the substances I! to be sorted, these being fedby a suitably placed channel l3.

Below the said perforated bottom is mounted a hopper l4 which is connected by a yielding bellows [5 with the discharge conduit I6 of a air fan I! in continuous operation. A valve 18 serves to regulate the, air blast which is thus delivered through the bottom Ill. a

The shaking table has at one end an orifice 25 for the discharge of the heavy substances, and at the other end, at the top' part of the raised edge, is located a channel 26 ,for the discharge of the light substances. An orifice 21 situated laterally at the middle of one side of the table, may be provided for the offtake of substances of medium weight.

At the top, the table is pivoted directly at 31, on each side ll, to-a long rod 38 secured at one end to the strap 39 of an eccentric 40 keyed to a rotatable shaft 4|. The other end of the rod 38 is pivoted at 42 to a suspension arm 43 which I is pivoted at 44 to the main frame.

Moreover, each side i I of the table is connected by a link 45 to a point 46 on a rod 41, which is shorter than the rod 38. Rod is pivoted at one end to the eccentric strap '39 at the same point as the rod. 38. The other end of rod 41 is connected at 48 to the free end of suspensionlink' 49, which is pivoted at 50 to the main frame. Arms or links 43 and 49 are identicalin length and occupy parallel positions. The distances between the point of attachment of rods 34 and 41 to the eccentric strap 39 and the points 31 and 46 are positioned to the lengths of arms 38 and 41, respectively.

The operation of the shaking table ranged is as iollows:

It will be supposed that the material tobe sorted such as raw coal, is supplied by the chan-' nel ll of the shaking table. The fan I3 is set running, as well as the motor actuating each eccentric 40. It is observed that the points of rods i 38 and 41 adjacent the eccentrics will describe thus arcomplete circles whose radius is the radius 01:

the said eccentrics. On the contrary, the outer ends of said rods describe circular arcs whose radius is equal to the length of the arms 43 and 49, that is, substantially straight lines. In consequence, the intermediate points such as the points 31 and 16 at which the table is attached to the rods 38 and 41, respectively, will move through closed trajectories whose form resembles that of an ellipse.

Due to the fact that the distances between the point of attachment of rods 38 and 41 to the eccentric strap and the points 31 and 46 are proportionaltothe'lengths of rods 38 and 41, the trajectories described by points I! and 46 are similar to the trajectories described by all points of the table.

The shaking projects the substances upwardly, and the pieces which are partially impeded in their descent by the upward current of air will be retarded in their fall according as they are lighter, so that the substances which drop again upon the perforated bottom will be situated ac cording to their density.

However, the improvements according to the present invention are particularly adapted, not only to sort, in the vertical direction, the substances supplied to the shaking table but'also to direct ,such' substances to their respective points otdischarge, that is, the heavy substancesto thev orifice and the light substances to the channel 26, and for this purpose, the current of air is given the necessary force, while the eccentrics 40 will have the required speed and stroke in order to comply with theoperating conditions to be further set forth with reference to Fig.2.

according to the arrow Fe, while the schist particle is projected at a later time according to the arrow Fl, so that the schist particle will be projected further to the right than the coal particle.

As all points of the shaking table describe the same substantially elliptical trajectories, the action Just described will take place at all points of the table, and thus the heavy pieces will have a general movement to the right, this movement taking place upon the whole length 0! the perforated bottom, so that tables of a great length may be readily constructed, and will operate in a very regular manner.

This will form a veritable bed of schist against the orifice 25, and since this orifice is preferablyv arranged on the siphon principle, these pieces of schist will only be'discharged when a suitable mass has been accumulated, and this obstructing bed will practically prevent all pieces of coal from passing through the schist.

From a practical standpoint, the respective movement of progression 01' the light and heavy substances are quite important, as this provides for an absolutely automatic separation of the substance, irrespectively of all irregularities in the feeding of the shaking table, and of the proportion of the light and heavy substances in the raw material. In particular, supposing that no heavy substance is contained in the material supplied to the table, no particle will be brought tocthe orifice 25, and there will be no loss of material.

0n the other hand, the substances of intermediate density will remain in position, without forward or backward motion, and will take a circular motion in the table.

Although such intermediate substances may be in small proportion, they will finally fill up the table, so that it. becomes necessary to discharge them throughthe lateral orifice 21. 'Alternately, it would be possible to evacuate such intermediate substances with the light substances, through the orifice 26, then transporting such partly sorted material to a second shaking table which is adapted for the sortingof these intermediate substances.

I claim:

1. A sorting apparatus of the type described comprising a frame, a table having a-peri'orated bottom, means for blowing air up through the perforated bottom, a rotating eccentric. mounted in said frame, links pivoted to said frame, levers of unequal length connected to the ends of said links and connected together to the eccentric at one side of the latter, means connecting the table to the levers of unequal length, the distances between the points of attachment of the table to each lever and the points of attachmentof each lever to the eccentric being proportional to the length of the respective levers.

2. Apparatus according to claim 1 comprising also an ofitake for lighter material at one end of the table, an oiftake for heavier material at the other end of the table, a baiiie near the last-mentioned end extending downwardly through the layer of lighter material on the table, and an ofitake located intermediate said ends of the table and communicatingwith middle layers of the material on the table.

, FRANCOIS JACQUES BAR BERRY. I 

